Telegraph plant or type-printing telegraph



May 24, 1932. A. JlPP TELEGRAPH PLANT OR TYPE PRINTING TELEGRAPH Filed Feb. 19, 1930 INVENTOR 4 uaus T J/ PP BY ATTORN EY5 Patented May 24, 1932 UNITED STATES PATENT OFFICE AUGUST J'IPP, OF BEBLIN-SPANDAU, GERMANY, ASSIGNOR T SIEMENS & HALSKE,

AKTIENGESELLSCHAFT, OF SIEMENSSTADT, NEAR BERLIN, GERMANY, A CORPORA- TION OF GERMANY TELEGRAPH PLANT OR TYPE-PRINTING TELEGRAPH Application filed February 19, 1930, Serial No. 429,739, and in Germany February 19, 1929.

My invention relates to improvements in telegraph plants or type-printing telegraphs, and more particularly in such plants in which the connection of the subscriber stations is effected by automatic switchgear located at one or a plurality of exchanges. In such plants it is usual to carry out the connecting lines between the stations and the exchange as two-wire lines while the through-connection of the telegraph lines within the exchange is preferably eifected by employing four wires with a view to enable the separate supervision of the two directions of traffic. One pair of wires is then provided for one direction of trafllc, for instance from the calling to the called subscribed, and the other pair for the opposite direction of trafiic.

It is, however, impossible to carry out the through-connection of such a large number of wires for each connection to be made, the more so as a fifth wire is as a rule provided for testing purposes, with the standard selectors employed in automatic telephony since these selectors are designed for the throughconnection of three wires only. The use of special selectors which differ from this stand-- ard construction would, however, render the operation of an automatic telegraph plant or type-printing telegraphs complicated and expensive.

My invention enables the standard selectors for connecting through three wires to be used, and under certain conditions an auto' matic telephone exchange may also be employed as exchange for telegraphy or typeprinting telegraphy.

According to my invention the reduction in the number of wires to be connected through is attained by changing-over ot each pair of Wires required for the opposite trans mission directions of a connection one wire only. Apart from these two wires a third wire for testing and similar purposes may be connected through in known manner. A further feature of my invention is the provision of a common connect-ion which is con, nected to the wire of each of the pairs of wires which is not connected to the switch arms and contacts of the selectors. As a common connector, one may use, for instance,

a busbar or a ground connection possessing a sufficiently large cross-sectional area.

My invention will be more readily understood on referring to the drawing afi'ixed to my specification which shows one embodi- 4 ment by way of example. The single figure of the drawing illustrates the wiring diagram of an exchange for automatic telegraphy or type-printing telcgraphy in which for the sake of simplification all switchgear immaterial for my invention has been omitted. The pilot wire, for instance, which at automatic exchanges is used for checking the engaged state, has thus not been shown in the drawing; for the purpose of simplifying the representation the connecting lines between the exchange and the subscriber station have also been assumed as consisting of two double-lines, one double line being destined for transmitting messages in one direction and the other for transmitting messages in the other direction.

The drawing shows on the left-hand side a subscriber station of which, however, only one transmitter relay S With the transmit ting contact 8 is shown and the receiving relay E with the receiving contact 6 The transmitting contact 8 is connected with the receiving relay E at the exchange by means of a pair of wires or lines L and the receiving relay E of the subscriber is connected with the transmitting contact 8 of the exchange by means of a second pair of wires or lines L. r

The advance of the selectors on the contact corresponding with the subscriber desired takes place by operating the driving magnet H from the calling subscriber station, the testing of the called-up subscriber for being engaged taking place by means of a testing equipment not shown. One of the selectors, the selector coordinated to the subscriber station mentioned, is represented by the contact arms 2' and is which may be moved over the contact 0, 2, 3 to which are connected the other subscribers.

Assuming that the subscriber 1 desires to reach the subscriber 8, the contact arms 1' and k are moved on to the contacts 3, which are connected to connecting lines a, and 6 of subscriber 3, by means of a corresponding number of current impulses. If the desired subscriber is disengaged a pilot relay (not shown) responds and p and 0 complete the connection through of the connecting lines so that the tratfic may commence. During the traffic a relay not shown is energized which disconnects the driving magnet of the selector H, by means of a contactin order to prevent a further advance of the selector.

The disconnection after the termination of the trafiic and the reversal of the selector takes place by influencing the relay lV which causes the return of the selector into the inoperative position and which, for instance, in known manner may act as releasing magnet mechanically on the switch members of the selector.

For the traffic between the two subscribers connected with each other two separate current tracks are provided which serve for the transmission of signals in the two 0 )posite directions of traffic. One of these circuits passes, for instance, from the battery across the contacts 6 the line 1, the contact of the pilot relay p the contact arm 2', selector contact 3 and line wire Z) to the transmitter relay which transmits the signal impulses to the subscriber called. The circuit for the opposite direction passes from the transmitting contact of the called subscriber across the line wire a contact 3, contact arm in, pilot contact 39 line 1 to the transmitter relay S which transmits the signal impulses to the subscriber called.

Of each pair of wires required for these two circuits one wire only is carried across the selectors while the other wire is replaced by a ground connection common to them all.

It will be" readily understood that my invention is by no means limited to the embodiment by way of example illustrated in the drawing but that it is equally well applicable to all other systems of connections ct automatic telegraph and type-printing telegraphs.

I claim as my invention:

In a telegraph or printing telegraph system employing two pairs of wires for the transmission of traffic in two directions, a plurality of subscriber stations, sending and receiving equipment operatively associated with each subscriber station for sending traffic in one direction over one pair of said wires and for receiving traffic in another direction over the other pair of said wires, an exchange connected to each of said subscriber stations via said two pairs of wires, an automatic switchgear in said exchange and circuits controlled by said switchgear for establishing connections between said subscribe-r stations for the transmission of trafiic in two directions, each of. said circuitscomprising a pair of wires, only one of said wires of each lastmentioned pair of wires being connected to said automatic switchgear.

2. In a telegraph or printing telegraph system employing two pairs of wires for the transmission of traflic in two directions, a plurality of subscriber stations, sending and receiving equipment operatively associated with each subscriber station for sending trafitic in one direction over one pair of said wires and for receiving traffic in another direction over the other pair of said wires, an exchange connected to each of said subscriber stations via said two pairs of wires, an automatic switchgear in said exchange and circuits controlled by said switchgear for establishing connections between said subscriber stations for the transmission of traffic in two directions, each of said circuits comprising a pair of wires, only one of said wires of each last-mentioned pair of wires being connected to said automatic switchgear and the other of said wires of each pair of wires from said subscriber stations being connected via a common connector.

3. In a telegraph or printing telegraph exchange system, a plurality of subscriber stations, sending and receiving equipment at each of said subscriberstations for sending traliic in one direction and for receiving traftic in the opposite direction, an exchange connected to each of said subscriber stations, automatic switchgear at said exchange and connections established by said switchgear to connect said subscriber stations, each of said connections comprising, within the exchange, two separate one-way transmission circuits for the transmission of traffic in one direction and in the opposite direction respectively, only one wire of each of said one-way trans mission c rcuits within the exchange being connected to said automatic switchgear.

4. In a telegraph or printing telegraph exchange system, a plurality of subscriber stations, sending and receiving equipment at each of said subscriber stations for sending tratiic in one direct-ion and for receiving traffie in the opposite direction, an exchange connected to each or said subscriber stations, automatic switchgear said. exchange and connections establi shed by saic. switchgear to connectsaid subscri er stations, each of said 'it within the two separate on -way transmission circuits on m? trafiic in one direction for the transr and in the opposite direction respectively, on one wire oi cn o; .ld cneway transn .,..on circuits within the exchange being connected to said automatic switchgear, and the other re of each of said one-way trans mission circuits within the exchange being connected via a common connector.

In testimony whereof I attix my signature.

AUGUST J IPP. 

